Fuze for a Projectile

ABSTRACT

A fuze ( 10 ) for a projectile, in particular for a spin-free projectile, having a first and a second arming criterion for the safety and arming unit ( 14 ) for the fuze ( 10 ), with the first arming criterion using the launch acceleration of the projectile ( 12 ) or of the fuze ( 10 ). The fuze ( 10 ) has pressure and/or temperature sensors ( 20 ) arranged at a distance from one another in order to measure the pressure and/or temperature difference during the Right phase of the projectile ( 12 ), with the respective difference measured value being compared by means of a comparator ( 24 ) with a predetermined threshold value ( 26 ), and with a corresponding comparison signal ( 28 ) forming the second arming criterion for the safety and arming unit ( 14 ) of the fuze ( 10 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a fuze for a projectile, in particular for a non-spinning or spin-free projectile, which possesses a first and a second arming criterion for its safety and arming unit, with the first arming criterion using the launch acceleration of the fuze.

2. Discussion of the Prior Art

In the case of projectiles that do not spin, such as mortars or the like, the launch acceleration is used as a first arming criterion. A safety break, for example, such as a pin or cotter, or latching device, is used as a second arming criterion, which must be withdrawn before the projectile is launched. A safety break, i.e., a safety pin, cotter, or latching device, such as this has the serious defect that the fuze of the projectile has only one safety feature once the safety break has been withdrawn, and nevertheless still has to be handled. This results in an increased risk to the operator. Furthermore, safety breaks such as these are not suitable for automatic weapons or launch systems.

Another possibility until now has been to use a wind-driven impeller or a turbine wheel, for example, as the second arming criterion, which is mounted in the fuze and senses the airflow after launch. For this purpose, the incident flow must strike the wind-driven impeller or turbine wheel via a channel which has an inlet and an outlet. This channel as well as the mounting for the wind-driven impeller or turbine wheel are sensitive to dirt and to icing, and are therefore unsuitable for use, for example, in sandy or dusty operating conditions and environments.

SUMMARY OF THE INVENTION

Against the background of these circumstances, the invention is based on the object of providing a fuze for a projectile, in particular for a projectile that does not spin, having a second arming criterion without any continuous channel being provided for the safety and arming unit, and with automatic arming being possible by simple means.

According to the invention, this object is achieved by the provision of a novel pressure/temperature sensor arrangement facilitating implementing a second arming criterion, as described hereinbelow. Preferred embodiments and developments of the invention are set forth in the dependent claims.

According to the invention, pressure sensors and/or temperature sensors are preferably fitted at the fuze tip and on the fuze circumference, which are suitable for carrying out a pressure-difference measurement and/or a temperature-difference measurement when air flows on them during the flight phase of a projectile, and for unambiguously detecting the respective flight phase of the projectile, as a function of a predetermined threshold value. A corresponding comparison signal between the predetermined threshold value and the pressure and/or temperature difference measurement signal forms the second arming criterion for the fuze according to the invention. This signal is therefore used as the second arming criterion, and leads to automatic arming of the fuze according to the invention.

The advantages achieved by the invention are that the safety for the user and the reliability are considerably improved, because the fuze is armed automatically, and because there are no openings into the interior of the fuze.

BRIEF DESCRIPTION OF THE DRAWING

Further details, features and advantages will become evident from the following description of one exemplary embodiment, which is illustrated schematically in the single figure of drawing, of a fuze, which is shown in the form of a section view, of a projectile, in particular of a spin-free projectile.

DETAILED DESCRIPTION OF THE INVENTION

The figure illustrates a fuze 10 for a projectile 12. The faze 10 has a safety and arming unit 14 with a first and a second arming criterion. The first arming criterion uses the launch acceleration of the projectile 12. An acceleration sensor 16, which is operatively connected to the safety and arming unit 14, is used to detect the launch acceleration. This operative connection is indicated by the bent arrow 18.

The fuze 10 has sensors 20 at a distance from one another. One sensor 20 is provided at the faze tip 22, and further sensors 20 are arranged at a distance from it, at equal intervals from one another along the circumference of the fuze 10. The sensors 20 are pressure sensors and/or temperature sensors. The pressure sensors 20 are suitable for measuring the pressure difference in accordance with Bernoulli's Law, and/or the temperature sensors are suitable for measuring the temperature difference when an incident airflow strikes the fuze 10, during the flight phase of the projectile, and for unambiguously detecting the flight phase of the projectile 12 as a function of a predetermined threshold value. For this purpose, the measurement signals produced by the sensors 20 are compared in a comparator 24 with the said threshold value. The threshold value is indicated by the arrow 26. The operative connection between the sensors 20 and the comparator 24 is represented by the bent arrow lines 28.

Once the flight phase of the projectile 12 has been unambiguously detected with the aid of the sensors 20, then the corresponding comparison signal forms the second arming criterion for the safety and arming unit 14 for the faze 10. This comparison signal is indicated by the arrow 30.

LIST OF REFERENCE SYMBOLS

10 Fuze (for 12)

12 Projectile

14 Safety and arming unit (of 10)

16 Acceleration sensor (of 10 for 14)

18 Arrow/operative connection/first arming criterion (for 14)

20 Sensors (of 10)

22 Fuze tip (of 10)

24 Comparator (of 10 for 20)

26 Threshold value (for 24)

28 Arrow/operative connection (between 20 and 24)

30 Arrow/comparison signal/second arming criterion (for 14) 

1. A fuze for a spin-free projectile, said fuze comprising a first and a second arming criterion for a safety and arming unit (14) of the fuze, said first arming criterion utilizing the launch acceleration of the fuze (10), the faze (10) including pressure and/or temperature sensors (20) arranged at a distance from one another for measuring the pressure and/or temperature difference; a comparator (24) for comparing the respective difference measured value with a predetermined threshold value (26), and a corresponding comparison signal (28) from the comparator forming the second arming criterion for the safety and arming unit (14) for the fuze (10) of the projectile (12).
 2. A faze according to claim 1, wherein at least one said sensor (20) is provided at the fuze tip (22), and a plurality of sensors (20) are arranged axially spaced at a distance from the fuze tip (22) along a circumference of the fuze (10).
 3. A fuze according to claim 2, wherein the sensors (20) are arranged at uniform intervals about the circumference of the fuze (10). 